The goal of this NIH Phase II proposal is to develop, fabricate and clinically test a dry micro-machined physiologic recording electrode that can be used without requiring electrolytes and/or skin preparation. Traditionally, the monitoring of human physiological data requires attaching electrodes to the skin with adhesive collars, tape, or collodion after the skin has been vigorously cleaned to reduce electrical contact impedance. This approach is both time-consuming and troublesome. Therefore, a need exists for physiological recording electrodes that do not require exorbitant technician set-up time and vigorous skin preparation of the patient to be monitored. The proposed dry physiological recording electrodes have an innovative micro-machined surface that enables fast application times without causing patient discomfort. Recent tests showed the feasibility of producing micro-topographical features on the dry electrode surface that penetrate through the high impedance dead skin cells making excellent electrical contact with the patient even on hairy parts of the test subject. The recorded physiological signals (EEG and EMG) were comparable to adjacently mounted conventional electrodes. This Phase II program will optimize and further develop micro-machined electrodes to collect EEG, EMG, EOG, ECG, etc, from a variety of patients regardless of skin thickness and amount of hair.